sync: centralize sync startup decisions in TryStart.

chrome/browser/signin/token_service.h

Index: chrome/browser/signin/token_service.h
diff --git a/chrome/browser/signin/token_service.h b/chrome/browser/signin/token_service.h
index 23743175f113e733a821e3451caec4e3acbb75bc..b4423cc522fb7e0f6d27bf10e42884d21f2893c6 100644
--- a/chrome/browser/signin/token_service.h
+++ b/chrome/browser/signin/token_service.h
@@ -144,7 +144,7 @@ class TokenService : public GaiaAuthConsumer,
   // Async load all tokens for services we know of from the DB.
   // You should do this at startup. Optionally you can do it again
   // after you reset in memory credentials.
-  void LoadTokensFromDB();
+  virtual void LoadTokensFromDB();
 
   // Clear all DB stored tokens for the current profile. Tokens may still be
   // available in memory. If a DB load is pending it may still be serviced.
@@ -197,6 +197,11 @@ class TokenService : public GaiaAuthConsumer,
       WebDataService::Handle h,
       const WDTypedResult* result) OVERRIDE;
 
+ protected:
+  void set_tokens_loaded(bool loaded) {
+    tokens_loaded_ = loaded;
+  }
+
  private:
 
   // Gets the list of all service names for which tokens will be retrieved.